Adobe Flash Vulnerability being used by Ransomware in Malvertising

Security researchers at Proofpoint discovered CryptoWall 2.0 ransomware used malvertising^# to infect the computers with outdated Adobe flash players running on Windows.

Without having to click on anything, visitors to the impacted websites which serve Adobe Flash enabled embedded advertisement may be stealthily infected with the ransomware which exploits the vulnerability of Adobe flash players (CVE-2014-0556). The impacted websites, including various service pages in the Yahoo, Match.com, and AOL domains, etc, potentially reaching as many as 3 million visitors per day. Similar to the behaviour of other ransomware, CryptoWall encrypts the files in the infected computers and demands the victims paying ransom in exchange of the encryption keys.

Malvertising (from "malicious advertising") attacks use online advertising channels to infiltrate malware into the computers of unsuspecting users by embedding malicious code within advertisements on legitimate websites.